1. Field of the Invention
The present invention relates to a canister mounted on an automobile for preventing the emanation of a vaporized fuel gas and, more particularly, to an improvement in the canister comprising a container having a vaporized fuel gas inlet port and an exit port, an aggregate of activated carbon in the container for adsorbing the vaporized fuel gas, and at least a pair of electrodes for heating the activated carbon through the resistance of the activated carbon, at the time of desorption of the vaporized fuel gas.
2. Description of the Prior Art
The present assignee has previously proposed a canister of this type in Japanese Patent Laid-Open No. 6-280694. The activated carbon is heated through the resistance of the activated carbon at the time of desorption of the vaporized fuel gas from the standpoint of raising the temperature of the vaporized fuel gas adsorbed by the activated carbon, in order to enhance the kinetic energy and to promote the desorption of the vaporized fuel gas from the activated carbon.
The canister is deteriorated by the accumulation of residual gas that remains adsorbed by the activated carbon but is not desorbed. In order to enhance the durability of the canister, the desorption must be effected efficiently and to a sufficient degree.
In the widely known canister using general activated carbon, however, an electric current flows in small amounts between the two electrodes due to a high electric resistance and, as a result, there is a problem that it is difficult to heat the activated carbon up to a required temperature.